Electronic device and fan

ABSTRACT

According to one embodiment, a fan includes a fan case comprising a first wall in which a first air inlet is formed, a second wall facing the first wall in which a second air inlet is formed, and a side wall which connects the first wall to the second wall and in which an air outlet is formed; a rotor comprising a shaft, an impeller fixed to the shaft, and an abutment portion, and contained in the fan case between the first and second walls and configured to rotate about the shaft; a bearing in the second wall and configured to support the shaft; and a prevention portion that disposed in the fan case and that the abutment portion can contact or separate from and that is configured to prevent the rotor from moving in a direction away from the bearing when the abutment portion contacts the prevention portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2011-080266, filed Mar. 31, 2011; the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to an electronic device and a fan.

BACKGROUND

Typically, electronic devices each of which is equipped with a fan are available. In such electronic devices, the fan comprises a fan case; a rotor that comprises an impeller and a rotary shaft, that is housed in the fan case, and that rotates about the axis of the rotary shaft; and a bearing for supporting the rotary shaft.

If such a typical fan is subjected to a shock by any reason, the rotor moves in the direction away from the bearing. That causes improper rotations of the rotor, which in turn leads to a decline in the air blowing capacity.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

A general architecture that implements the various features of the invention will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the invention and not to limit the scope of the invention.

FIG. 1 is an exemplary perspective view of a mobile personal computer according to a first embodiment;

FIG. 2 is an exemplary plan view of the mobile personal computer in the first embodiment;

FIG. 3 is an exemplary rear perspective view of the mobile personal computer in the first embodiment;

FIG. 4 is an exemplary perspective view of a fan in the first embodiment;

FIG. 5 is an exemplary bottom view of the fan in the first embodiment;

FIG. 6 is an exemplary cross-sectional view of the fan in the first embodiment;

FIG. 7 is an exemplary plan view of an impeller in the first embodiment;

FIG. 8 is an exemplary cross-sectional view of the fan according to a first modification example of the first embodiment;

FIG. 9 is an exemplary cross-sectional view of the fan according to a second modification example of the first embodiment;

FIG. 10 is an exemplary cross-sectional view of the fan according to a second embodiment;

FIG. 11 is an exemplary cross-sectional view of a movement restriction mechanism in the second embodiment;

FIG. 12 is an exemplary cross-sectional view of the movement restriction mechanism according to a first modification example of the second embodiment;

FIG. 13 is an exemplary cross-sectional view of the movement restriction mechanism according to a second modification example of the second embodiment;

FIG. 14 is an exemplary cross-sectional view of the movement restriction mechanism according to a third modification example of the second embodiment;

FIG. 15 is an exemplary cross-sectional view of the movement restriction mechanism according to a fourth modification example of the second embodiment;

FIG. 16 is an exemplary cross-sectional view of the movement restriction mechanism according to a fifth modification example of the second embodiment;

FIG. 17 is an exemplary cross-sectional view of the fan according to a third embodiment;

FIG. 18 is an exemplary cross-sectional view of the fan according to a modification example of the third embodiment;

FIG. 19 is an exemplary cross-sectional view of the fan according to a fourth embodiment;

FIG. 20 is an exemplary cross-sectional view of the fan according to a fifth embodiment;

FIG. 21 is an exemplary cross-sectional view of the fan according to a sixth embodiment;

FIG. 22 is an exemplary cross-sectional view of the fan according to a modification example of the sixth embodiment;

FIG. 23 is an exemplary cross-sectional view of the fan according to a seventh embodiment;

FIG. 24 is an exemplary cross-sectional view of the fan according to a modification example of the seventh embodiment;

FIG. 25 is an exemplary plan view of the mobile personal computer according to an eighth embodiment;

FIG. 26 is an exemplary perspective view of a personal computer according to a ninth embodiment; and

FIG. 27 is an exemplary perspective view of a television receiver according to a tenth embodiment.

DETAILED DESCRIPTION

In general, according to one embodiment, an electronic device comprises a housing, a display device, a fan case, a rotor, an opening, and a prevention portion. A first opening and a second opening are formed in the housing. The display device is contained in the housing and comprises a display screen which is exposed through the first opening. The fan case is contained in the housing and comprises a first wall in which a first air inlet is formed, a second wall which faces the first wall and in which a second air inlet is formed, and a side wall which connects the first wall to the second wall. An air outlet from which air to be supplied to the second opening is discharged is formed in the side wall. The rotor comprises a column member, an impeller fixed to the column member, and an abutment portion. The rotor is contained in the fan case between the first wall and the second wall and is configured to rotate about an axis of the column member. The opening is formed in the second wall. At least a portion of the column member is disposed in the opening. The prevention portion is disposed in the fan case. The abutment portion can contact or separate from the prevention portion. The prevention portion is configured to prevent the column member from moving in a direction away from the opening when the abutment portion contacts the prevention portion.

First Embodiment

According to a first embodiment, a notebook-sized mobile personal computer 1, which functions as an electronic device and as a television receiver, comprises a rectangular and flat first main body 2 and a rectangular and flat second main body 3 as illustrated in FIG. 1. The first main body 2 and the second main body 3 are connected in a relatively rotatable manner via a joint 4.

In the first main body 2; a display panel 6, which is a display device such as a liquid crystal display (LCD) having a touch panel 5 on the front face (i.e., on a display screen 6 a) thereof, and a push button mechanism 7 are arranged in an exposed manner on a front face 2 b that is the external face of a housing 2 a. Similarly, in the second main body 3; a display panel 9, which is a display device such as an LCD having a touch panel 8 on the front face (i.e., on a display screen 9 a) thereof, and a push button mechanism 10 are arranged in an exposed manner on a front face 3 b that is the external face of a housing 3 a. Meanwhile, in the first embodiment, for the sake of simplicity; the width direction (horizontal direction) of the second main body 3 is defined as the X direction, the apical direction of the second main body 3 is defined as the Y direction, and the height direction of the second main body 3 is defined as the Z direction. Herein, the X axis, the Y axis, and the Z axis are mutually orthogonal.

In the open state of the mobile personal computer 1 illustrated in FIG. 1, the display panel 6 and a cover body 7 a of the push button mechanism 7 as well as the display panel 9 and a cover body 10 a of the push button mechanism 10 lie in an exposed condition. In such open state, the user is able to perform operations. In contrast, in the folded state (not illustrated) of the mobile personal computer 1, the front faces 2 b and 3 b face each other from up close in such a way that the display panel 6 and the cover body 7 a of the push button mechanism 7 are hidden by the housing 2 a; while the display panel 9 and the cover body 10 a of the push button mechanism 10 are hidden by the housing 3 a. In the present embodiment, the touch panels 5 and 8, the push button mechanisms 7 and 10, and a microphone (not illustrated) function as input operation modules; while the display panels 6 and 9 and speakers (not illustrated) function as output operation modules. Meanwhile, in a mobile personal computer having a keyboard, or click buttons, or a pointing device (not illustrated); the keyboard or the click buttons also function as input operation modules.

The joint 4 is a component for joining the first main body 2 to the second main body 3, and is configured separately from the first main body 2 and the second main body 3. The joint 4 joins an end portion 2 c at the base end of the first main body 2 with an end portion 3 c at the base end of the second main body 3. At the central part in the longitudinal direction of an end edge 2 d of the end portion 2 c and at the central part in the longitudinal direction of an end edge 3 d of the end portion 3 c, respectively; rectangular notches 2 e and 3 e are formed except over the respective ends. Each of the rectangular notches 2 e and 3 e comprises a long opening along the longitudinal direction and has only a shallow depth. Half of the joint 4 is inserted in the notch 2 e and the remaining half thereof is inserted in the notch 3 e. The joint 4 is set to have a length L that is slightly shorter than the width of the notches 2 e and 3 e. Moreover, the joint 4 is set to have a width W that is substantially equal to the thickness of the mobile personal computer 1 when the first main body 2 and the second main body 3 are closed together in the folded state.

The first main body 2 and the joint 4 are joined in a relatively rotatable manner around a rotation axis Ax1 via a first hinge mechanism 11A. Similarly, the second main body 3 and the joint 4 are joined in a relatively rotatable manner around a rotation axis Ax2 via a second hinge mechanism 11B. The rotary shafts Ax1 and Ax2 lie parallel to each other. In the present embodiment, the first hinge mechanism 11A and the second hinge mechanism 11B are coupled together so that the relative rotation angle around the rotation axis Ax1 of the first main body 2 with respect to the joint 4 is identical to the relative rotation angle around the rotation axis Ax2 of the second main body 3 with respect to the joint 4. However, the two relative rotation directions with respect to the joint 4 are opposite to each other. Thus, when the user operates the joint 4 for the purpose of opening either one of the first main body 2 and the second main body 3, the mobile personal computer 1 falls into the open state. Similarly, when the joint 4 is operated for the purpose of closing either one of the first main body 2 and the second main body 3, the mobile personal computer 1 falls into the folded state. Moreover, when the user opens the first main body 2 and the second main body 3, the mobile personal computer 1 falls into the open state. Similarly, when the first main body 2 and the second main body 3 are closed, the mobile personal computer 1 falls into the folded state.

Herein, the display panels 6 and 9 are formed in the shapes of flat and rectangular parallelepipeds, and are housed in the housing 2 a and 3 a, respectively. Moreover, the display panels 6 and 9 receive display signals from control circuits (not illustrated), which are configured with an electronic component 22 or the like that is mounted on a substrate 23 disposed inside the housing 3 a of the second main body 3. As a result, each of the display panels 6 and 9 displays pictures including stationary pictures and motion pictures. Herein, the electronic component 22 is, for example, a central processing unit (CPU). The light that represents the pictures displayed on the display screen 6 a of the display panels 6 and on the display screen 9 a of the display panel 9 is output anteriorly through the touch panels 5 and 8, respectively, which are colorless and transparent in nature. Meanwhile, the control circuits in the mobile personal computer 1 are a picture signal processing circuit, a tuner, an HDMI signal processing module (HDMI stands for high-definition multimedia interface), an audio-video (AV) input terminal, a remote-control signal receiving module, a control module, a selector, an onscreen display interface, a memory module (such as a read only memory (ROM), a random access memory (RAM), or a hard disk drive (HDD)), an audio signal processing circuit, an interface circuit, and various controllers (no control circuit is illustrated). Meanwhile, the mobile personal computer 1 also comprises built-in speakers (not illustrated) for the purpose of audio output.

As illustrated in FIGS. 2 and 3, the housing 3 a of the second main body 3 comprises a mask 20 and a case 21 constituting the outer housing. Herein, the mask 20 and the case 21 constituting the outer housing are integratedly coupled by screwing, engagement, or fitting; and form the outline of the housing 3 a. The housing 3 a houses the display panel 9 that comprises the display screen 9 a exposed on the front side, and also houses the substrate 23 that is fixed to the case 21 via an inner plate. On the mask 20 is formed a first opening 20 a, through which is exposed the display screen 9 a of the display panel 9. If put in another way, the first opening 20 a serves as an LCD opening.

On the case 21, air inlets 3j are formed at a rear end 21 b at the base end side of a bottom wall 21 a. In the first embodiment, the air inlets 3 j represent a collection of a plurality of (a number of) small holes formed through the bottom wall 21 a. Moreover, the air inlets 3 j (i.e., the region having small holes formed thereon) are formed over a comparatively elongated region along an end edge 21 c. On the case 21 is also formed an air outlet 3 h as a second opening. Inside the housing 3 a, a ventilation flue is installed from the air inlets 3 j up to the air outlet 3 h. Midway in the ventilation flue is installed a fan 50, the explanation of which is given later. The air taken in from the air inlets 3 j due to the fan 50 is then thrown out from the air outlet 3 h. As a result, components such as the electronic component 22 mounted on the substrate 23 get cooled.

Moreover, in the case 21 is disposed an engaging member 3 m at a position close to the fan 50 and the air inlets 3 j. The engaging member 3 m is, for example, a claw (claw of latch mechanism) for enabling engagement and disengagement between the first main body 2 and the second main body 3. The engaging member 3 m itself can engage with or disengage from the first main body 2.

In the first embodiment, as illustrated in FIG. 2, the fan 50 is disposed inside the housing 3 a of the second main body 3. The fan 50 performs ventilation inside the housing 3 a so that the components such as the electronic component 22 mounted on the substrate 23 get cooled.

As illustrated in FIGS. 4 to 6, the fan 50 comprises a fan case 51, a rotor 52, a bearing 53, and a motor 54. In the first embodiment, the fan 50 is assumed to be a centrifugal fan. Moreover, for the sake of convenience, gaps between the components are illustrated in an enlarged manner in FIG. 6.

The fan case 51 comprises a first wall 51 a and a second wall 51 b that form a pair of opposite walls, and comprises a side wall 51 c that joins the first wall 51 a to the second wall 51 b. If put in another way, the fan case 51 serves as a casing or a housing. The fan case 51 is disposed in the thickness direction of the housing 3 a in such a manner that at least some portion of the fan case 51 overlaps with the display panel 9.

In the first wall 51 a is formed a first air inlet 51 d and in the second wall 51 b are formed a plurality of second air inlets 51 e. In contrast, in the side wall 51 c is formed a air outlet 51 f. In the central part of the second wall 51 b is formed an island-shaped mounted wall 51 h. Meanwhile, each of the second air inlets 51 e is formed between a pair of adjacent spokes 51 g. Moreover, the first air inlet 51 d, which is formed on the first wall 51 a, is positioned opposite to an abutment portion 58 described later.

The first wall 51 a is made of, for example, metal That makes it possible to make the first wall 51 a comparatively thinner. Herein, the first wall 51 a represents a top panel. The second wall 51 b and the side wall 51 c are integratedly formed using resin. On the side wall 51 c, the first wall 51 a is detachably locked with a locking mechanism such as a claw 51 k. The first wall 51 a does not have the bearing 53 disposed thereon. The second wall 51 b represents a bottom wall.

Thus, as described above, the fan case 51 is housed inside the housing 3 a, and comprises the first wall 51 a in which is formed the first air inlet 51 d; comprises the second wall 51 b in which are formed the second air inlets 51 e and which lies opposite to the first wall 51 a; and comprises the side wall 51 c in which is formed the air outlet 51 f serving as a second opening. The air to be supplied to the air outlet 3 h or the air reaching the air outlet 3 h is discharged from the air outlet 51 f. The side wall 51 c joins the first wall 51 a to the second wall 51 b.

As illustrated in FIG. 6, the rotor 52 comprises a impeller 61 and a rotary shaft 62. The rotor 52 is housed in the fan case 51 and rotates about the axis of the rotary shaft 62. If put in another way, the rotor 52 rotates about the axis of the rotary shaft 62 as the rotating shaft (shaft). The rotary shaft 62 is elongated along the direction in which the first wall 51 a and the second wall 51 b face each other. In the first embodiment, the rotary shaft 62 represents a column member, while the rotor 52 represents a rotary member.

The impeller 61 comprises abase 61 a to which is fixed one end of the rotary shaft 62 and comprises a plurality of blades 61 c extending from a periphery 61 b of the base 61 a. The impeller 61 is made of resin or metal. The base 61 a is cuplike in shape and comprises an opening facing toward the second wall 51 b. More specifically, the base 61 a comprises a base wall 61 f that is disc-like in shape and comprises a side wall 61 g extending from the peripheral border of the base wall 61 f toward the second wall 51 b. The outer periphery of the side wall 61 g serves as the periphery 61 b of the base 61 a. On the inner surface of the base wall 61 f is formed a concave shaft fastening member 61 h in which one end of the rotary shaft 62 is inserted and fastened.

As illustrated in FIGS. 6 and 7, on the outer periphery of the impeller 61 is formed an annular joining member 61 d, which joins the outer borders of the blades 61 c facing the first wall 51 a. Of the joining member 61 d, an end 61 e on the side of the first wall 51 a is formed to have a bent shape. More specifically, starting from the inner peripheral region toward the outer peripheral region, the end 61 e is formed to bend (tilt) away from the first wall 51 a.

The bearing 53 is disposed in the fan case 51 for the purpose of supporting the rotary shaft 62 in a rotatable manner. The bearing 53 is cylindrical in shape and is configured as, for example, a fluid dynamic bearing or an oil retaining bearing. Alternatively, the bearing 53 can also be configured as a ball bearing. The bearing 53 is fit in an opening 51 p that is formed on the inside of a cylindrical member 51 i, which is erected on the inner surface of the second wall 51 b. As a result, the bearing 53 gets fixed to the second wall 51 b. On that portion on the inner surface of the second wall 51 b which serves as the base of the cylindrical member 51 i, a thrust plate 55 is fixed that supports the other end face of the rotary shaft 62 along the axial direction thereof. The opening 51 p in which the bearing 53 is fit is formed on the second wall 51 b. In the opening 51 p is housed at least a part of the rotor 52 representing a column member. The bearing 53 represents a support that houses at least a part of the rotor 52, which is a rotating member, and that supports the rotor 52 in a rotatable manner.

As illustrated in FIG. 6, the motor 54 comprises a stator 54 a, a rotor 54 b that surrounds the stator 54 a, and a circuit board 54 c. The stator 54 a further comprises an iron core 54 e equipped with a winding wire 54 d. The rotor 54 b further comprises a cylindrical yoke 54 f and a plurality of magnets 54 g that are fixed spaced apart from each other on the inner periphery and along the circumferential direction of the yoke 54 f. Meanwhile, the yoke 54 f is fixed on the inner periphery of the side wall 61 g of the base 61 a. To the circuit board 54 c is connected an electrically-conductive lead 56. Thus, the circuit board 54 c receives electrical power from the electrically-conductive lead 56 and transmits that electrical power to the winding wire 54 d. In the motor 54, due to the electromagnetic action between the magnets 54 g and the stator 54 a facing the magnets 54 g, the rotor 54 b rotates thereby causing the rotor 52 to rotate.

In the fan 50 is formed a movement restriction mechanism 57 that restricts the rotor 52 from moving in the direction away from the bearing 53. The movement restriction mechanism 57 comprises the abutment portion 58 that is formed in the rotor 52 and a prevention member 59 that is formed in the fan case 51.

The abutment portion 58 is formed on the base 61 a. More specifically, the outer surface at the central portion of the base wall 61 f of the base 61 a constitutes the abutment portion 58.

The prevention member 59 is formed on the outside of the bearing 53, and comprises a projection 59 a and a support member 59 b. The prevention member 59 is fixed to an outer surface 51 j of the first wall 51 a of the fan case 51. The support member 59 b is rod-like in shape and is disposed across the first air inlet 51 d. Moreover, the both ends of the support member 59 b are fixed to the outer surface 51 j of the first wall 51 a by means of, for example, adhesion or screwing. Thus, the support member 59 b is disposed on the outer surface 51 j of the first wall 51 a and comprises the projection 59 a fixed thereto in an integrated manner. The projection 59 a protrudes from the support member 59 b toward the abutment portion 58, and is inserted in the first air inlet 51 d and lies inside the fan case 51. The projection 59 a can come into and out of contact with the abutment portion 58. The abutment portion 58 can contact or separate from the projection 59 a. Between the projection 59 a and the abutment portion 58 exists a clearance of a predetermined distance L1, which is shorter than a minimum distance L2 between the first wall 51 a of the fan case 51 and the rotor 52 in the state when the predetermined distance L1 is secured. In such a configuration, it is possible to reduce the rotational resistance of the rotor 52. In the present embodiment, the prevention member 59 is formed on the fan case 51 and can come into and out of contact with the abutment portion 58. By abutment against the abutment portion 58, the prevention member 59 functions as a restricting member and prevents the rotary shaft 62, which represents a column member, from moving away from the opening 51 p. Moreover, the prevention member 59 is formed on the inner surface of the housing 3 a that covers the side opposite to the display screen 9 a of the display panel 9. Hence, the prevention member 59 restricts the rotor 52 from moving in the opposite direction of the display panel 9. Furthermore, the prevention member 59 is formed in the outside of the bearing 53, which represents a support portion, and when the prevention member 59 contacts the rotor 52 (the abutment portion 58), the prevention member 59 prevents the rotor 52 from moving away from the bearing 53.

Usually, due to the force of attraction (magnetic force) between the magnets 54 g and the stator 54 a, the rotor 52 is able to either rotate or stop rotating while maintaining the restriction distance L1 between the projection 59 a and the abutment portion 58. However, if the fan 50 gets subjected to a shock, then there are times when the rotor 52 resists such force of attraction and moves in the direction away from the bearing 53. With regard to that issue, the abutment portion 58 formed on the rotor 52 comes into contact with the prevention member 59 formed in the fan case 51. As a result, the prevention member 59 restricts the rotor 52 from moving in the direction away from the bearing 53. If put in another way, by abutment against the abutment portion 58, the prevention member 59 restricts the rotary shaft 62, which represents a column member, from moving away from the opening 51 p. The prevention member 59 prevents the rotary shaft 62 from moving in the direction away from the opening 51 p when the abutment portion 58 contacts the prevention member 59. Once the impact of the shock disappears, then the rotor 52 returns to the position of maintaining the restriction distance L1 between the projection 59 a and the abutment portion 58. In this way, in the first embodiment, the rotor 52 is restricted from moving along the axial direction. Meanwhile, in the first embodiment, since the engaging member 3 m is disposed at a position close to the fan 50, the vibrations generated due to the movement of the engaging member 3 m easily reach the fan 50. Moreover, if a component such as a memory is installed near the fan 50, then the vibrations generated due to such installation also easily reach the fan 50.

As explained above, in the first embodiment, the prevention member 59 abuts against the abutment portion 58 so as to restrict the rotor 52 from moving in the direction away from the bearing 53. That makes it possible to prevent the impeller 61 of the rotor 52 from making contact with the first wall 51 a of the fan case 51. As a result, even in case the fan 50 gets subjected to a shock, the impeller 61 can successfully keep on rotating. That prevents a decline in the air blowing capacity of the fan 50.

Moreover, in the first embodiment, the prevention member 59 is disposed on the outside of the bearing 53. Hence, as compared to the case when the prevention member 59 is disposed on the inside of the bearing 53, it becomes possible to simplify the configuration as well as simplify the manufacturing process. Besides, the reliability of the bearing 53 also remains intact.

Moreover, since the prevention member 59 abuts against the abutment portion 58 so as to restrict the rotor 52 from moving in the direction away from the bearing 53, it also becomes possible to prevent the rotor 52 from getting positionally-fixed (locked) while making contact in a tilted manner with the fan case 51. That helps in preventing the noise from occurring.

Furthermore, in the first embodiment, the end 61 e of the joining member 61 d that lies on the side of the first wall 51 a is formed to have a bent shape. Hence, even in case the rotor 52 tilts and makes contacts with the fan case 51, it becomes possible to prevent the rotor 52 from getting hung up on the fan case 51. That in turn makes it possible to prevent the rotor 52 from getting positionally-fixed (locked) while making contact in a tilted manner with the fan case 51. Besides, if a lubricant agent is applied to the area at which the impeller 61 may come into contact with the first wall 51 a, it becomes possible to prevent the impeller 61 from getting hung up on the first wall 51 a. As the lubricating agent, it is possible to use, for example, wax.

Explained below is a first modification example of the first embodiment. As illustrated in FIG. 8, in the fan 50 according to the first modification example; the abutment portion 58, which constitutes the movement restriction mechanism 57 and which is formed in the rotor 52, is formed to be a projection. Herein, the abutment portion 58 protrudes toward the prevention member 59. Meanwhile, unlike the abovementioned configuration, the prevention member 59 constituting the movement restriction mechanism 57 does not comprise the projection 59 a. Besides, the abutment portion 58 can come into and out of contact with one surface 59 c of the support member 59 b of the prevention member 59. In such a configuration, the prevention member 59 abuts against the abutment portion 58 so as to restrict the rotor 52 from moving in the direction away from the bearing 53.

Explained below is a second modification example of the first embodiment. As illustrated in FIG. 9, unlike the abovementioned configuration, the fan 50 according to the second modification example does not comprise the joining member 61 d. Besides, an end 611 of each blade 61 c facing the first wall 51 a has a bent shape. In such a configuration, even in case the rotor 52 tilts and makes contacts with the fan case 51, it becomes possible to prevent the rotor 52 from getting hung up on the fan case 51.

Second Embodiment

In a second embodiment, the movement restriction mechanism 57 comprises a different configuration than the configuration according to the first embodiment. As illustrated in FIG. 10, the prevention member 59 of the movement restriction mechanism 57 is formed inside the fan case 51. Herein, in an identical manner to the first embodiment, the fan case 51 comprises the second wall 51 b serving as the wall on which the bearing 53 is disposed.

As illustrated in FIG. 11, the abutment portion 58 of the movement restriction mechanism 57 protrudes from a periphery 62 a of the rotary shaft 62. Herein, the abutment portion 58 is formed to be annular in shape and gets fit in a ring-like groove 62 b that is formed on the periphery 62 a of the rotary shaft 62. The portion of the abutment portion 58 that protrudes from the periphery 62 a of the rotary shaft 62 is annular in shape.

The prevention member 59 of the movement restriction mechanism 57 is formed on the second wall 51 b. More specifically, the prevention member 59 is fixed to the second wall 51 b using the cylindrical member 51 i. Moreover, the prevention member 59 is formed to be annular in shape and is fixed to an inner periphery 51 m of the cylindrical member 51 i. The prevention member 59 is positioned opposite to the abutment portion 58 and can come into and out of contact with the abutment portion 58. Moreover, in the prevention member 59, an annular member 63 is disposed on the side of the second wall 51 b in such a way that the abutment portion 58 is positioned between the prevention member 59 and the annular member 63.

In such a configuration, the prevention member 59 abuts against the abutment portion 58 so as to restrict the rotor 52 from moving in the direction away from the bearing 53.

Moreover, in the second embodiment, the abutment portion 58 restricts the movement of oil that flows out of the bearing 53. That makes it possible to prevent the spread of oil to the outside of the fan case 51.

Explained below are modification examples of the second embodiment.

As illustrated in FIG. 12, in the movement restriction mechanism 57 according to a first modification example, the prevention member 59 is rod-like (salient-like) in shape and is fixed on the inner periphery 51 m of the cylindrical member 51 i.

As illustrated in FIG. 13, in the movement restriction mechanism 57 according to a second modification example, the abutment portion 58 is formed in an integrated manner with the rotary shaft 62. The abutment portion 58 is annular in shape and protrudes from the periphery 62 a of the rotary shaft 62. The prevention member 59 comprises the same configuration to the configuration according to the first modification example. In such configurations too, the prevention member 59 abuts against the abutment portion 58 so as to restrict the rotor 52 from moving in the direction away from the bearing 53.

As illustrated in FIG. 14, in the movement restriction mechanism 57 according to a third modification example, the abutment portion 58 is rod-like in shape and protrudes from the periphery 62 a of the rotary shaft 62. Consequently, the protruding portion of the abutment portion 58 that protrudes from the periphery 62 a of the rotary shaft 62 is salient-like in shape. Herein, the abutment portion 58 is fit into a hole 62 c that is formed on the rotary shaft 62.

As illustrated in FIG. 15, in the movement restriction mechanism 57 according to a fourth modification example, the abutment portion 58 is formed in an integrated manner with the rotary shaft 62. The abutment portion 58 is rod-like in shape and protrudes from the periphery 62 a of the rotary shaft 62. Consequently, the protruding portion of the abutment portion 58 that protrudes from the periphery 62 a of the rotary shaft 62 is salient-like in shape.

As illustrated in FIG. 16, in the movement restriction mechanism 57 according to a fifth modification example, the abutment portion 58 is rod-like (shaft-like) in shape and protrudes on both sides from the periphery 62 a of the rotary shaft 62. Consequently, the protruding portions of the abutment portion 58 that protrude from the periphery 62 a of the rotary shaft 62 are salient-like in shape. Herein, the abutment portion 58 is fit into a hole 62 d that is formed on the rotary shaft 62.

In each of the abovementioned modification examples, the prevention member 59 abuts against the abutment portion 58 so as to restrict the rotor 52 from moving in the direction away from the bearing 53.

Third Embodiment

In a third embodiment, the movement restriction mechanism 57 comprises a different configuration than the configuration according to the first embodiment. As illustrated in FIG. 17, the prevention member 59 of the movement restriction mechanism 57 is a projection that protrudes toward the fan 50 from an inner plate 3 g, which constitutes the housing 3 a of the second main body 3. Meanwhile, the abutment portion 58 comprises the same configuration as the configuration according to the first embodiment and is formed in the rotor 52.

In such a configuration too, the prevention member 59 abuts against the abutment portion 58 so as to restrict the rotor 52 from moving in the direction away from the bearing 53.

Explained below is a modification example of the third embodiment. As illustrated in FIG. 18, in the fan 50 according to the modification example; the abutment portion 58, which constitutes the movement restriction mechanism 57 and which is formed in the rotor 52, is formed to be a projection. Herein, the abutment portion 58 protrudes toward the prevention member 59. Meanwhile, the prevention member 59 constituting the movement restriction mechanism 57 is flat-like in shape. Besides, the abutment portion 58 can come into and out of contact with the prevention member 59. In such a configuration, the prevention member 59 abuts against the abutment portion 58 so as to restrict the rotor 52 from moving in the direction away from the bearing 53.

Fourth Embodiment

In a fourth embodiment, as illustrated in FIG. 19, the configuration differs from the first embodiment in the point that the housing 3 a comprises a bent portion 3 n along which the fan 50 is bent.

In the fan case 51, the first wall 51 a comprises a bent portion 510 that is bent along the bent portion 3 n. Herein, the first wall 51 a of the fan case 51 forms a concave shape (valley-like shape) along the bent portion 3 n. Similarly, in the fan case 51, the second wall 51 b comprises a bent portion 51 n that is bent along the bent portion 3 n. Moreover, each blade 61 c comprises a bent portion 61 m that is bent along the bent portion 3 n.

In such a configuration, since the fan 50 is bent along the bent portion 3 n, it can be ensured that the fan 50 has sufficient air blowing capacity.

Besides, since the first wall 51 a of the fan case has a concave shape (valley-like shape), it becomes possible to prevent a contact between the rotor 52 and the first wall 51 a even if the rotor 52 tilts.

Fifth Embodiment

In a fifth embodiment, as illustrated in FIG. 20, the configuration differs from the first embodiment in the point that the first wall 51 a of the fan case 51 in the fan 50 has a projection-like shape (mountain-like shape). More particularly, the first wall 51 a has such a projection-like shape in which, starting from the ends toward the central part, the first wall 51 a goes on moving away from the second wall 51 b.

In such a configuration, even in case the rotor 52 tilts and makes contacts with the first wall 51 a, the area of contact is limited to a comparatively small contact point thereby making it possible to prevent the rotor 52 from getting hung up on the fan case 51. That in turn makes it possible to prevent the rotor 52 from getting positionally-fixed (locked) while making contact in a tilted manner with the fan case 51.

Sixth Embodiment

In a sixth embodiment, the movement restriction mechanism 57 comprises a different configuration than the configuration according to the first embodiment. As illustrated in FIG. 21, the prevention member 59 of the movement restriction mechanism 57 is formed inside the fan case 51. Herein, in an identical manner to the first embodiment, the fan case 51 comprises the second wall 51 b serving as the wall on which the bearing 53 is disposed.

The abutment portion 58 of the movement restriction mechanism 57 is formed in one of the blades 61 c. Herein, the abutment portion 58 is formed as a substantially L-shaped locking toggle in which a first portion 58 d and a second portion 58 e, which extends toward the rotary shaft 62, form a substantially right angle.

The prevention member 59 of the movement restriction mechanism 57 is formed on the second wall 51 b. Herein, the prevention member 59 is formed to be annular in shape and surrounds the cylindrical member 51 i. Moreover, the prevention member 59 comprises a cylindrical first portion 59 d and an annular flanged second portion 59 e that is formed on the outer periphery of the cylindrical first portion 59 d. The second portion 58 e of the abutment portion 58 can come into and out of contact with the second portion 59 e of the prevention member 59.

In such a configuration, the prevention member 59 abuts against the abutment portion 58 so as to restrict the rotor 52 from moving in the direction away from the bearing 53.

Explained below is a modification example of the sixth embodiment. In the modification example, as illustrated in FIG. 22, the second portion 58 e of the abutment portion 58 extends from the first portion 58 d in the direction going away from the rotary shaft 62. The second portion 59 e of the prevention member 59 is formed on the inner periphery of the first portion 59 d.

In such a configuration too, the prevention member 59 abuts against the abutment portion 58 so as to restrict the rotor 52 from moving in the direction away from the bearing 53.

Seventh Embodiment

In a seventh embodiment, as illustrated in FIG. 23, the configuration differs from the first embodiment in the point that a salient-like second abutment portion 71 is formed on the rotor 52 and an annular-projection-like third abutment portion 72 is formed in the fan case 51. The second abutment portion 71 and the third abutment portion 72 are made of, for example, resin.

The second abutment portion 71 protrudes from the joining member 61 d. That is, the second abutment portion 71 is formed on the outer peripheral region of the rotor 52. Meanwhile, the third abutment portion 72 protrudes from the inner surface of the first wall 51 a. The second abutment portion 71 and the third abutment portion 72 are spaced apart opposite to each other. The distance between the second abutment portion 71 and the third abutment portion 72 is equal to the minimum distance L2, which is the also the distance between the first wall 51 a of the fan case 51 and the rotor 52. Meanwhile, alternatively, the second abutment portion 71 can be formed in the fan case 51, while the third abutment portion 72 can be formed on the rotor 52.

In such a configuration, even in case the rotor 52 tilts thereby causing a contact between the second abutment portion 71 and the third abutment portion 72, the area of contact is limited to a comparatively small contact point thereby making it possible to prevent the rotor 52 from getting hung up on the fan case 51. That in turn makes it possible to prevent the rotor 52 from getting positionally-fixed (locked) while making contact in a tilted manner with the fan case 51.

Explained below is a modification example of the seventh embodiment. As illustrated in FIG. 24, in the modification example, the second abutment portion 71 is formed in the base 61 a and the third abutment portion 72 is formed on the first wall 51 a of the fan case 51 at a position opposite to the second abutment portion 71. Alternatively, the second abutment portion 71 can be formed in the fan case 51 and the third abutment portion 72 can be formed on the rotor 52.

In such a configuration too, even in case the rotor 52 tilts thereby causing a contact between the second abutment portion 71 and the third abutment portion 72, the area of contact is limited to a comparatively small contact point thereby making it possible to prevent the rotor 52 from getting hung up on the fan case 51. That in turn makes it possible to prevent the rotor 52 from getting positionally-fixed (locked) while making contact in a tilted manner with the fan case 51.

Eighth Embodiment

In an eighth embodiment, as illustrated in FIG. 25, the configuration differs from the first embodiment in the point that the mobile personal computer 1 is a slate-type mobile personal computer. Basically, the mobile personal computer 1 according to the eighth embodiment comprises the same configuration as the configuration of the second main body 3 according to the first embodiment. More particularly, the mobile personal computer 1 comprises a flat housing 100; a display panel 102, which is a display device such as an LCD having a touch panel 101 on the front face thereof; the fan 50 housed in the housing 100; the substrate 23; and the electronic component 22 mounted on the substrate 23. In the housing 100 are formed the air inlets 3 j and the air outlet 3 h. Moreover, inside the housing 100, a ventilation flue is installed starting from the air inlets 3 j to the air outlet 3 h. Midway in the ventilation flue is installed the fan 50. Besides, on the housing 100 is formed a first opening 100 a, through which is exposed a display screen 102 a of the display panel 102.

In such a configuration, the fan 50 is identical to that described in the first embodiment. Hence, in an identical manner to the first embodiment, even in case the fan 50 gets subjected to a shock, the impeller 61 can successfully keep on rotating. That prevents a decline in the air blowing capacity of the fan 50. Meanwhile, the fan 50 need not be identical to that described only in the first embodiment. That is, it is also possible to implement the fan 50 according to the other embodiments or modification examples described above.

Herein, although it is described with reference to the abovementioned embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth. For example, the embodiments are explained with reference to a notebook-sized mobile personal computer having two display screens or a slate-type mobile personal computer having a single display screen. However, alternatively, the embodiments are also applicable to other electronic devices or television receivers comprising a fan. For example, the embodiments are also applicable to notebook-sized personal computers or desktop computers having a keyboard, personal digital assistants (PDAs), smartbooks, smartphones, or cellular phones. Therein, FIG. 26 is an illustration diagram of a notebook-sized personal computer 200 having a keyboard 201 (according to a ninth embodiment), and FIG. 27 is an illustration diagram of a television receiver 300 (according to a tenth embodiment).

In this way, according to an aspect of the embodiments, it is possible to prevent a decline in the air blowing capacity of a fan.

Moreover, the various modules of the systems described herein can be implemented as software applications, hardware and/or software modules, or components on one or more computers, such as servers. While the various modules are illustrated separately, they may share some or all of the same underlying logic or code.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions. 

1. An electronic device comprising: a housing comprising a first opening and a second opening; a display device in the housing, the display device comprising a display screen exposed through the first opening; a fan case in the housing, the fan case comprising a first wall comprising a first air inlet, a second wall facing the first wall and comprising a second air inlet, and a side wall connecting the first wall to the second wall and comprising an air outlet from which air supplied to the second opening is discharged; a rotor in the fan case between the first wall and the second wall and configured to rotate about an axis of a column member, the rotor comprising the column member, an impeller fixed to the column member, and an abutment portion; an opening in the second wall and in which at least a portion of the column member is disposed; and a prevention portion in the fan case and configured to contact or separate from the abutment portion, the prevention portion configured to prevent the column member from moving in a direction away from the opening when the abutment portion contacts the prevention portion.
 2. The electronic device of claim 1, wherein the fan case is configured so that at least a portion of the fan case overlaps the display device.
 3. The electronic device of claim 2, wherein the prevention portion is configured on an inner surface of the housing that covers a side opposite to the display screen of the display device and is configured to prevent the rotor from moving in a direction opposite to the display device.
 4. A fan comprising: a fan case comprising a first wall comprising a first air inlet, a second wall facing the first wall and comprising a second air inlet, and a side wall connecting the first wall to the second wall and comprising an air outlet; a rotor in the fan case between the first wall and the second wall and configured to rotate about a shaft, the rotor comprising the shaft, an impeller fixed to the shaft, and an abutment portion; a bearing in the second wall and configured to support the shaft; and a prevention portion in the fan case and configured to contact or separate from the abutment portion, the prevention portion configured to prevent the rotor from moving in a direction away from the bearing when the abutment portion contacts the prevention portion.
 5. The fan of claim 4, wherein the impeller comprises a base and a plurality of blades extending from a periphery of the base, the base is fixed to one end of the shaft, the abutment portion is disposed in the base, and the prevention portion is disposed in the first wall.
 6. The fan of claim 4, wherein the prevention portion comprises a projection configured to contact the abutment portion and a support portion, the support portion is disposed on the outer surface of the first wall and fixed to the projection.
 7. The fan of claim 4, wherein the prevention portion is inside the fan case.
 8. The fan of claim 4, wherein the abutment portion is on the shaft and configured to protrude from a periphery of the shaft, and the prevention portion is on the second wall.
 9. An electronic device comprising: a fan comprising a fan case, a rotor, and a support member, the support member configured to contain at least a portion of the rotor and rotatably support the rotor; and a prevention portion on an outside of the support member and configured to prevent the rotor from separating from the support member when the prevention portion contacts the rotor. 